This invention relates to a hand-held navigation plotter or xe2x80x9cPLOT""TIMERxe2x80x9d for use with a marine or aeronautical chart. The plotter is in the form of a thin plastic straight edge containing visually readable scales corresponding to the scales of the charts. By placing the plotter on the chart, course and distance problems, as well as, time, rate, and fuel burn may be solved for any trip.
Travel, by any means, includes the elements of planning and execution. Because of the ever changing conditions encountered during the execution phase, the plan must be continually changed to accommodate the unplanned conditions and reach a successful conclusion.
In marine and aeronautical travel, a detailed plan is usually completed before departure. The plans may have a standard format and include all the known variables that may affect the trip. The plans are completed using the latest information available concerning such things as the tides, currents, weather, wind, traffic etc. Also, the planning is partly based on performance data of the vehicle that does not necessarily reflect the current capabilities of the ship. Therefore, the plan represents a theoretically perfect voyage that begins at a certain time and place and ends at a certain time and place.
However, as soon as the starting time has passed the reality of the situation begins to change the theoretical. Once the ship has cast off or the airplane has taken off, the crew is responsible for the safe completion of the trip and making all corrections to adjust for real-time changed conditions not allowed for in the plan. To accomplish this objective, the ships are properly equipped and the crews are properly trained.
The ships, both air and water, are of two types. There are crewed vehicles and there are vehicles operated by a single person. Clearly, the crewed vessel has the advantage of allowing one person to control the vehicle while others solve problems as they arise. In the single-handed operation, one must maintain control of the vehicle while making the required changes to the plan. Regardless, of the number of people involved, a quick, timely, and correct answer must be forthcoming to avoid further damage to the plan and, possibly, the participants.
A conventional plotter in wide spread use, by pilots, is a clear plastic straight-edge with a 180 degree compass rose on one side. The straight-edge is used to make the course line on a chart and measure the distance. The compass rose is placed on the latitude or longitudinal lines of the chart to determine the true course.
A similar plotter is disclosed in U.S. Pat. No. 4,190,960, issued Mar. 4, 1980 to Warner. This plotter has a circular disk rotatably mounted on the body of the plotter with 360 degrees marked thereon. The disk must be rotated to determine the compass course of the flight path.
A rotary slide ruler is usually used in conjunction with these plotters to determine time, rate, distance and fuel questions.
Acetate film jackets and envelopes are used to cover or house charts and allow information to be entered on tables present on the acetate.
There are various lap boards, including several scales and tables, that may be supported by the legs of the pilot or helmsman. These devices have been reduced further to a knee board that may be strapped about a leg of the captain.
Small hand-held electronic computers have also come into use for solving navigation/fuel problems.
All of these devices require coordinating information from different sources, sequentially, and applying that information to yet another set of references or devices to get a solution. The amount of time and attention necessary for performing these tasks, as well as, the time required for organizing the different implements takes away from the concentration needed to control the craft.
What is lacking in the prior art is a simple hand-held navigation plotter, with no moving parts, that can be placed on a chart and determine time, rate, distance, course and fuel requirements visually, without calculations.
Accordingly, it is an objective of the instant invention to provide a simple hand-held navigation plotter to be placed on a navigation chart to determine distance and course, visually.
It is a further objective of the instant invention to provide a hand-held plotter including tables, used in conjunction with a timepiece or stop watch to determine speed and time.
It is yet another objective of the instant invention to provide a plotter with structure capable of measuring an arc or a segment of a circle.
It is a still further objective of the invention to provide a plotter used in conjunction with the fuel flow instruments to determine fuel requirements.
It is a further objective of the invention to provide a plotter that can be manipulated with one hand to determine time, rate, distance, course, and fuel needs visually or with simple calculations.
It is another objective of the invention to provide a plotter for use in VFR and IFR conditions.
Other objects and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of this specification and include exemplary embodiments of the present invention and illustrate various objects and features thereof.